Linux containers vs. VMs: A security comparison (InfoWorld)

Over at InfoWorld, Jim Reno compares the security of virtual machines (VMs) and containers. "Which is more secure?" is a question that is often asked, but the answer, of course, is "it depends". Reno analyzes the attack surface of each to help in the choosing between VMs and containers."Many legacy VM applications treat VMs like bare metal. In other words, they have not adapted their architectures specifically for VMs or for security models not based on perimeter security. They might install many services on the same VM, run the services with root privileges, and have few or no security controls between services. Rearchitecting these applications (or more likely replacing them with newer ones) might use VMs to provide security separation between functional units, rather than simply as a means of managing larger numbers of machines.Containers are well suited for microservices architectures that "string together" large numbers of (typically) small services using standardized APIs. Such services often have a very short lifetime, where a containerized service is started on demand, responds to a request, and is destroyed, or where services are rapidly ramped up and down based on demand. That usage pattern is dependent on the fast instantiation that containers support. From a security perspective it has both benefits and drawbacks."